Anyone (modder especially) who wants this game improved I guess ... probably not you.

After some more tests I must say that any new weapon addon which inherits from these sniper rifles class, is facing the same issue.

Confirmed also that Sniper units making any mission unplayable into dedicated servers .. the error message is ...

You cannot play/edit this mission; it depends on downloadable content
A3_weapons_f_longrangerifles_gm6

It is a good way for BIS to "prove" that is respecting their Greek clients despite the incident took place in Greece with their collegues. After all no player is responsible for its Country authorities ... IMHO